LabView 2020.1- value recording in a certain range

[juliala]

Hello all,
In an experiment I would like to record three different parameters. These are the temperature, the volume flow and the pressure. Here the temperature and the volume flow are variable. I have a cooling process from ambient temperature to 15°C. When the 15°C and a certain volume flow are reached, the temperature and the volume flow should remain constant for about 3s and then record the values. Up to now I have worked with a mask and limit test, which then outputs false or true to a case structure. However, it does not work. Can someone help me?
Many thanks already!
Many greetings
Julia

[GerdW]

Hi Julia,

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@juliala wrote:

When the 15°C and a certain volume flow are reached, the temperature and the volume flow should remain constant for about 3s and then record the values.

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You need to define "certain" and "for about" more exactly.

Then you can analyze the data you read from your device if they meet your criteria!

(No need for that MaskLimitTest ExpressVI, a simple InRangeAndCoerce will give the same result here (according to your desciption)…

[juliala]

Hello GerdW,

thank you for your quick answer. When the temperature is 15°C, the flow rates 30l/min, 70l/min and 100l/min are to be started and a measured value is to be taken at 15°C/30l & 15°C/70l & 15°C/100l. To then record a measured value, it is to be checked over a period of 3 seconds whether the values remain constant. If the two values are then constant, a value is to be recorded. The reason why I have not taken the InRangeAndCoerce that I understood that if the values do not fit into the value range, that these are forced into the range.

Hope it was better explained

Best regards, Julia

[GerdW]

Hi Julia,

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@juliala wrote:

The reason why I have not taken the InRangeAndCoerce that I understood that if the values do not fit into the value range, that these are forced into the range.

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InRangeAndCoerce has two outputs: the "coerced value" and the "in range?" boolean.

You can use one of them and omit the other…

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@juliala wrote:

it is to be checked over a period of 3 seconds whether the values remain constant. If the two values are then constant, a value is to be recorded.

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Checking real measurement values for being "constant" is not a good definition, there always will be noise added to your signal…

That's why I suggested to use InRangeAndCoerce: you can easily check for values within a certain range around your setpoint!